Electrolysis device and related detergentless washing machine

ABSTRACT

An electrolysis device is disclosed for producing alkaline water from water including an electrolysis vessel, a positive electrode, a negative electrode, a bipolar membrane element, and at least one cation exchangeable membrane within the electrolysis vessel. The bipolar membrane element has a cation exchangeable side and an anion exchangeable side, the cation exchangeable side being closer to the negative electrode than the anion exchangeable side. The at least one cation exchangeable membrane is arranged between the anion exchangeable side of the bipolar membrane element and the positive electrode, so as to define an alkali chamber between the bipolar membrane element and the cation exchangeable membrane. An ionic exchange resin is associated with the vessel, whereby flow of the water though the vessel and the ionic exchange resin produces alkaline water in the alkali chamber. Various options and modifications are possible. A related washing machine such as a dishwasher is also disclosed.

FIELD OF THE INVENTION

The subject matter disclosed herein relates generally electrolysis devices useful for cleaning and to related washing machines that can operate without use of detergent.

BACKGROUND OF THE INVENTION

Most clothes washers and dishwashers use detergents to clean the desired objects (clothing or cookware). Various formulations of detergents have been introduced that provide excellent cleaning in either type of machine. For example, clothes washers often use a surfactant such as a linear alkylbenzenesulfonates, usually along with water softeners, bleaches, enzymes, etc. Dishwashers also use surfactants, water softeners, bleaches, enzymes, and other ingredients.

Detergents have become substantially more environmentally sensitive over the years in terms of wastewater processing concerns of the various ingredients. However, use of detergents generally requires use of rinse cycles, which in turn requires that additional water and energy be used by the machine. Further, additional wastewater is generated during such a rinse cycle, requiring additional treatment in a septic or sewage system.

In order to avoid or reduce use of detergents, detergentless ionic washing has been proposed in clothing and dishwashers. For example, a number of such ionic washers are disclosed in US 2009/0159448, owned by Applicants' Assignee, and incorporated by reference herein. In that patent application, alkaline water is produced for detergentless washing in various embodiments of electrolysis devices. However, due to the low conductivity of typical tap water, energy consumption of such ionic devices may be high. Also, undesirable scaling may occur in some such systems in some conditions. Accordingly, an improved detergentless ionic washing system would be welcome.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

According to certain aspects of the disclosure, an electrolysis device is disclosed for producing alkaline water from water including an electrolysis vessel, a positive electrode, a negative electrode, a bipolar membrane element, and at least one cation exchangeable membrane within the electrolysis vessel. The bipolar membrane element has a cation exchangeable side and an anion exchangeable side, the cation exchangeable side being closer to the negative electrode than the anion exchangeable side. The at least one cation exchangeable membrane is arranged between the anion exchangeable side of the bipolar membrane element and the positive electrode, so as to define an alkalic chamber between the bipolar membrane element and the cation exchangeable membrane. An ionic exchange resin is associated with the vessel, whereby flow of the water though the vessel and the ionic exchange resin produces alkaline water in the alkalic chamber. Various options and modifications are possible.

According to certain other aspects of the disclosure, a detergentless washing machine includes a washing compartment for washing objects and an electrolysis vessel for supplying alkaline water to the washing compartment. The electrolysis vessel includes a positive electrode, a negative electrode, a bipolar membrane element, and at least one cation exchangeable membrane within the electrolysis vessel. The bipolar membrane element has a cation exchangeable side and an anion exchangeable side, the cation exchangeable side being closer to the negative electrode than the anion exchangeable side. The at least one cation exchangeable membrane is arranged between the anion exchangeable side of the bipolar membrane element and the positive electrode, so as to define an alkalic chamber between the bipolar membrane element and the cation exchangeable membrane. An ionic exchange resin is associated with the vessel, whereby flow of the water though the vessel and the ionic exchange resin produces the alkaline water in the alkalic chamber to be provided to the washing compartment for washing the objects. Again, various options and modifications are possible.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 provides a schematic view of a washer having an electrolysis device according to certain aspects of the disclosure;

FIG. 2 provides a schematic view of one possible electrolysis device useful in the washer of FIG. 1;

FIG. 3 provides a schematic view of another possible electrolysis device useful in the washer of FIG. 1;

FIG. 4 provides a schematic view of another possible electrolysis device useful in the washer of FIG. 1; and

FIG. 5 provides a schematic view of another possible electrolysis device useful in the washer of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 illustrates an exemplary washing machine 10. The exemplary washing machine 10 may include for example a cabinet 12, a hinged door 14, a washing compartment 16 in which washing of objects occurs, a water supply 18, and a water outlet 20. If desired, water supply 18 may include separate hot and cold water supplies (not shown). Water supply 18 and outlet 20 are connected to washing compartment 60 in conventional ways. Washing compartment 16 could be fixed (as in a dishwasher or the like) or could include a movable/rotatable drum within a larger container (as in a clothes washer or the like). Washing compartment 16 could include various conventional items within it such as sprayers, racks, tumbling structures, vents and drains, etc., as desired.

Washing machine 10 may include a user interface 22 including one or more input devices such as buttons, and one or more output devices such as displays, LED's, etc. A conventional controller 24, for example including a memory and processor, within washing machine 10 may receive and send signals from user interface 22 and other components of the device (not shown for clarity as unnecessary to fully disclose and explain the present inventive concepts), such as pumps, motors, valves, containers, sensors, power sources, rectifiers, etc., as are known to perform desired washing activities and cycles.

It should therefore be understood that washing machine 10 could comprise a clothes washer, a dish washer, a medical device sterilizer, or any other water-based machine for washing items. Therefore, conventional components of such devices as mentioned above could be adapted to employ the detergentless cleaning devices disclosed herein.

FIG. 1 further schematically shows an electrolysis device 28 located within washing machine 10 and including an electrolysis cell 30. A container 32 holds the alkaline product of electrolysis device 30. Conduits 34 and 36 connect container 32 to electrolysis device 30, and conduit 38 connects container 32 to washing compartment 16. A container 40 holds the acidic product of electrolysis device 30. Conduits 42 and 44 connect container 40 to electrolysis device 30, and conduit 46 connects container 40 to washing compartment 16. Electrolysis device 30 may receive water from water supply 18 as well via conduit 48.

As shown in FIG. 2, a cell unit 50 includes a positive electrode 52 and a negative electrode 54. The electrodes may be highly porous metals, such as titanium mesh for example. The cell unit includes a vessel 56 and a number of cells 58, 60, 62, and 64. The cells are divided by ion exchange membranes 66,68, and 70. Membrane 66 is an anion exchange membrane, membrane 70 is a cation exchange membrane, and membrane 68 is a bipolar exchange membrane. Membrane 68 has an anion exchange side 72 and a cation exchange side 74.

Inlets 76,78,80 and 82 and outlets 84,86,88, and 90 are provided for the cells 58-64, respectively. Each cell has within it a mixture of both cation and anion exchange resins 92 which may be any of a number of commercially available resins. For example, the resins may be cross-linked divinylbenzene, if desired. The cation exchange resin may have as a functional group a sulfonic group (—SO3H or −SO3Na), and the anion exchange resin may have as a the functional group a quaternary amine group.

An acid container 94 and an alkaline container 96 are provided as well. Acid container 94 has a first outlet 98 connected to cell inlets 78 and 82, and a second outlet 100 that is connected to a desired end use location, such as the interior of a washer 10. An inlet 102 is connected to cell outlets 86 and 90. Acidic liquid can thus cycle through cells 60 and 64 (acidic chambers) and container 94 via a pump (not shown). Alkaline container 96 has a first outlet 104 is similarly connected to cell inlets 76 and 80 and a second outlet 106 connected to a desired end use location. Inlet 108 is connected to cell outlets 84 and 88. Alkaline liquid can thus cycle through cells 58 and 62 (alkalic chambers) in a similar fashion.

Cells 58-64 should be large enough to generate sufficient alkaline water for cleaning the desired objects in a reasonable amount of time. For example, if used in a dishwasher, typical wash cycles vary from 30-75 minutes or so, depending on the device and the chosen cycle. Therefore, the size, flow rate, current, etc. can be chosen to obtain an amount of alkaline water needed for a given cycle. To generate 1.2 gallons of alkaline water of a pH of over 11, for example, might require cells with membranes as large as 10×20 cm, that run for an amount of time such as 20-25 minutes or so. Such alkaline water can be used in a dishwasher instead of detergent to clean cookware during a typical cleaning cycle. The acidic water generated can be used during rinsing to sanitize or sterilize as well.

The presence of the ion exchange resins within the cells allows the cells to operate while reducing CaCO₃ scaling and other such deposits on the ion exchange membranes while still allowing the chemical and electrical reactions to occur. It is believed that the regeneration of H and OH ions caused by the ion exchange resins beneficially prevents such scaling deposits. Further, by placing the ion exchange resins in the cells, the resins do no wear out, or will do so much more slowly so that they need not be changed out during the life of the product.

FIG. 3 shows a variation of cell unit 50 of FIG. 2. In FIG. 3, like parts receive like reference numerals, so all need not be mentioned herein. Cell unit 150 of FIG. 3 differs from that of FIG. 2 in that cells 158-164 do not include mixtures of ion exchange resins. Instead, anion exchange resins 191 are located in cells 158 and 162, and cation exchange resins 193 are located in cells 160 and 164. Resins may be of the types described above. Splitting the resins on a per cell basis may provide better performance in certain situation in terms of higher acid and alkaline generation at a given set of parameters.

FIG. 4 shows another modified version in which mixed resins may be employed. However, cell unit 250 of FIG. 4 includes three separate cells on each side of bipolar membrane 268 and formed by additional exchange membranes. As shown, cells 258 and 262 are connected to alkaline container 296, as before. Cells 260 and 264 are connected to acidic container 294 in similar fashion. Membranes 265 and 270 are cation exchange membranes and membranes 266 and 271 are anion exchange membranes. Cells 259 and 263 are connected to a water cycle. Ion exchange resins 292 are mixed as illustrated, but could be separated out according to anion and cation as above, if desired. Therefore, cell 250 provides a further separated system in which feed water can be provided as needed via a separate inlet. The feed water need not be circulated as shown, but may simply be provided to the washing device or drained after cycling though cell 20. Cell 250 may thus provide another arrangement for created alkaline water and acidic water for cleaning, while providing a ready source of water to the device as substances are used during cleaning.

Finally, FIG. 5 shows an alternate device in which cell 350 is a modified version of cells 50 and 150 above. In cell 350, however, separate containers 395 and 397 are provided for the anion exchange resin 391 and the cation exchange resin 393, respectively. Placing the exchange resins exterior to cell 350 does provide a number of the regenerative and anti-scaling benefits discussed above. However, in case performance degrades over time due to the resins and/or other portions of the cell becoming fouled or scaled, the resins can be replaced in containers 395 and 397 without having to replace the entire cell vessel 356. In some applications, this may be sufficient to provide the benefits mentioned above while still allowing for maintenance. Alternatively. The resins can be periodically changed on a regular schedule regardless of any fouling, degradation, etc., if desired to ensure peak performance of cell 350.

Accordingly, using the various electrolytic devices above and variations as disclosed, a detergentless wash can be achieved using alkalic and/or acidic water. In a dishwasher, sufficient alkalic water can be generated in a typical cycle amount of time, using minimal electric power as compared to the entire power demand of the machine, to suitably clean cookware using approximately 1.2 gallons of alkalic water at approximately 11 pH or more. Thus, detergent need not be employed, providing cost and environmental benefits. It should be understood that the electrolytic device herein may be used with various applications, including clothes and dish washing devices. However, other washing devices and other devices requiring alkaline and/or acidic water may be practiced using the present teachings.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. An electrolysis device for producing alkaline water from water comprising: an electrolysis vessel; a positive electrode, a negative electrode, a bipolar membrane element, and at least one cation exchangeable membrane within the electrolysis vessel, the bipolar membrane element having a cation exchangeable side and an anion exchangeable side, the cation exchangeable side being closer to the negative electrode than the anion exchangeable side, the at least one cation exchangeable membrane being arranged between the anion exchangeable side of the bipolar membrane element and the positive electrode, so as to define an alkalic chamber between the bipolar membrane element and the cation exchangeable membrane; and an ionic exchange resin associated with the vessel, whereby flow of the water though the vessel and the ionic exchange resin produces alkaline water in the alkalic chamber.
 2. The electrolysis device of claim 1, wherein an acidic chamber is defined between the anion exchange membrane and the bipolar membrane, whereby flow of the water though the vessel and the ionic exchange resin produces acidic water from the acidic chamber.
 3. The electrolysis device of claim 1, further including an anion exchangeable membrane between the negative electrode and the cation exchangeable side of the bipolar membrane element, an acidic chamber being defined between the anion exchangeable membrane and the bipolar membrane element, whereby flow of the water though the vessel and the ionic exchange resin produces acidic water from the acidic chamber.
 4. The electrolysis device of claim 3, wherein a second alkalic chamber is defined between the cation exchange membrane and the bipolar membrane, whereby flow of the water though the vessel and the ionic exchange resin produces alkaline water from the second alkalic chamber.
 5. The electrolysis device of claim 1, further including a container for holding the alkaline water produced by the alkalic chamber and for supplying the alkaline water either back to the alkalic chamber or to an end use location.
 6. The electrolysis device of claim 2, further including a container for holding the acidic water produced by the acidic chamber and for supplying the acidic water either back to the acidic chamber or to an end use location.
 7. The electrolysis device of claim 1, wherein the ionic exchange resin is located within the alkalic chamber of the electrolysis vessel.
 8. The electrolysis device of claim 2, wherein the ionic exchange resin is located within the acidic chamber of the electrolysis vessel.
 9. The electrolysis device of claim 1, wherein the ionic exchange resin is held within a container located outside of the and in liquid communication with the electrolysis vessel.
 10. The electrolysis device of claim 1, wherein the ionic exchange resin in the alkalic chamber is an anion exchange resin.
 11. The electrolysis device of claim 2, wherein the ionic exchange resin in the acidic chamber is a cation exchange resin.
 12. The electrolysis device of claim 2, wherein the ionic exchange resin in the alkalic chamber and the acidic chamber is a mixture of anion exchange resins and cation exchange resins.
 13. A detergentless washing machine comprising: a washing compartment for washing objects; and an electrolysis vessel for supplying alkaline water to the washing compartment, the electrolysis vessel including: a positive electrode, a negative electrode, a bipolar membrane element, and at least one cation exchangeable membrane within the electrolysis vessel, the bipolar membrane element having a cation exchangeable side and an anion exchangeable side, the cation exchangeable side being closer to the negative electrode than the anion exchangeable side, the at least one cation exchangeable membrane being arranged between the anion exchangeable side of the bipolar membrane element and the positive electrode, so as to define an alkalic chamber between the bipolar membrane element and the cation exchangeable membrane; and an ionic exchange resin associated with the vessel, whereby flow of the water though the vessel and the ionic exchange resin produces the alkaline water in the alkalic chamber to be provided to the washing compartment for washing the objects.
 14. The washing machine of claim 13, wherein an acidic chamber is defined between the anion exchange membrane and the bipolar membrane, whereby flow of the water though the vessel and the ionic exchange resin produces acidic water from the acidic chamber.
 15. The washing machine of claim 13, further including a container for holding the alkaline water produced by the alkalic chamber and for supplying the alkaline water either back to the alkalic chamber or to an end use location.
 16. The washing machine of claim 14, further including a container for holding the acidic water produced by the acidic chamber and for supplying the acidic water either back to the acidic chamber or to an end use location.
 17. The washing machine of claim 13, wherein the ionic exchange resin is located within the alkalic chamber of the electrolysis vessel.
 18. The washing machine of claim 14, wherein the ionic exchange resin is located within the acidic chamber of the electrolysis vessel.
 19. The washing machine of claim 1, wherein the ionic exchange resin is held within a container located outside of the and in liquid communication with the electrolysis vessel. 